Independently and not as an agent of the U.S. Government, the contractor shall attemto to do furter studies on the "natural killer cell" with regard to the antigenic target, the nature of the affector cell, and the locus of the H-2 linked reactivity gene; Develope appropriate methods to remove "non-specific" killer cells from human lymphocyte suspensions. Study the reactivity patterns in the residual primarily T-cell populations particularly in breast carcinoma and sarcoma patients; and Do exploratory studies to test the validity of the "syngenic restrictions" phenomenon in relation to tumor associated antigens.